Rubio reopened the door to running after speaking with Florida Lt. Gov. Carlos López-Cantera, a close friend of his who is running to replace him.
Sunday's mass shooting at an Orlando nightclub that left 49 dead made him rethink his decision, Rubio said.
“Obviously, I take very seriously everything that’s going on — not just Orlando, but in our country,” he said. “I enjoy my service here a lot. So I’ll go home later this week, and I’ll have some time with my family, and then if there’s been a change in our status, I’ll be sure to let everyone know.”
Rubio has until next week to decide whether to enter the GOP primary for his seat. 
Politico reported Wednesday that López-Cantera had urged Rubio to jump in the race, saying he would back out if the senator ran for reelection.
Another candidate for the seat, Rep. David Jolly (R-Fla.), said that he would make an announcement on Friday as to whether he would stay in the race.
Rubio said last year that he would not run for president and his Senate seat at the same time, a decision many Republican leaders have urged him to reconsider since he ended his presidential bid in March.